Antioxidant heterocyclic nitrogenous aromatic containing oil compositions

ABSTRACT

Lubricating oil compositions containing antioxidant mixtures of heterocyclic nitrogenous aromatic compounds derived from uintaite which function to prevent the oxidative thickening of lubricant oils at high temperatures.

nited States Patent Hellmuth et al.

[ Nov. 25, 1975 ANTIOXIDANT HETEROCYCLIC NITROGENOUS AROMATIC CONTAININGOIL COMPOSITIONS Inventors: Walter W. Hellmuth, Hopewell Junction;Walter D. Foucher, Jr., Fishkill; William R. Siegart, Poughkeepsie, allof NY.

Assignee: Texaco Inc., New York, NY.

Filed: Aug. 19, 1974 Appl. No.: 498,356

US. Cl 252/32.7 E; 252/33; 252/50; 252/401 Int. CL ClOM 1/48;ClOM3/42;C1OM 1/32; ClOM 3/26 Field of Search 252/327 E, 33, 33.4, 50,252/401 [56] References Cited UNITED STATES PATENTS 3,788,992 1/1974Sullivan 252/50 3,793,200 2/1974 Billings 252/327 E 3,846,312 11/1974Cross et al 252/50 Primary Examiner-Delbert E. Gantz AssistantExaminer-l. Vaughn Attorney, Agent, or FirmT. H. Whaley; C. G. Ries;Robert A. Kulason Lubricating oil compositions containing antioxidantmixtures of heterocyclic nitrogenous aromatic compounds derived fromuintaite which function to prevent the oxidative thickening of lubricantoils at high ABSTRACT temperatures.

15 Claims, No Drawings ANTIOXIDANT I-IETEROCYCLIC NITROGENOUS AROMATICCONTAINING OIL COMPOSITIONS BACKGROUND OF INVENTION There exists aconstant demand for improved lubricating oil compositions atsignificantly reduced cost. This demand has had specific impact in thesearch for antioxidants capable of controlling the thickening tendenciesof lubricants and specifically crankcase engine oils at elevatedtemperatures.

The utilization, as effective antioxidants, of compositions recovered inthe course of mining natural occurring, asphalitic type materialswell-known and employed commercially for other applications would renderthe cost of recovering the latter materials less expensive whileproviding antioxidants of substantially unparalleled economy.

Thus, the discovery of a motor oil composition containing an effective,valuable and inexpensive antioxidant lubricant additive produced withcomparative ease would represent a significant advance in the relevantart. This is particularly true where the recovered compositions requireonly minimal and inexpensive treatment to provide antioxidants ofsubstantially uniform effectiveness.

SUMMARY OF INVENTION It is accordingly an object of this invention toprovide improved lubricating oil compositions.

It is a further object of this invention to provide lubricant oilcompositions containing an antioxidant suitable for reducing thethickening of engine oils and particularly crankcase engine oils at hightemperatures.

It is an additional object in accordance with this invention to producethe antioxidant additive from naturally occurring asphaltites requiringminimal processing prior to utilization as antioxidants.

Thus, it has now been discovered that the thickening propensity ofcrankcase engine oils under high temperature operating conditions, forexample, crankcase bulk oil temperatures of 300F. and above, may bealleviated significantly by incorporation therein of the inexpensiveby-products derived from the mining of the naturally occurring resin,uintaite, in a mineral oil base of lubricating viscosity. The foregoingby-products are composed substantially of heterocyclic amines, includingalkyl substituted and unsubstituted quinolines, pyrroles, indoles andpyridines, it is believed.

; DETAILED DESCRIPTION OF THE INVENTION Specifcally, the inventionrelates to hydrocarbon mineral oil formulations containing anantioxidant capable of controlling the thickening tendencies of saidformulations, particularly under high temperature operating conditions,said antioxidant prepared by treatment of uintaite, a natural resin ofthe asphaltite type, found particularly in the Uinta Basin of Utah.

More specifically, the antioxidants employed in the practice of theinvention are derived from unitaite by the following processes:

Uintaite is subjected to cracking temperatures within the range of 885to 910F., and most desirably about 900F. to yield a fraction boiling inthe range of about 204 to about 343C. [400 to 650F.] and frequentlyreferred to as the diesel cut which, when treated with a non-oxidizing,strong mineral acid, for example, concentrated sulfuric acid,hydrochloric acid, phosphoric acid or trichloro-acetic acid, yields anacid phase which is readily separated from an accompanyingacid-insoluble organic phase. This latter extractive step isaccomplished most desirably at or about ambient temperature,particularly where concentrated sulfuric acid is employed, to avoidhydrolysis to which the acid phase is thereafter subjected in a separatestep preferably at a temperature within the range of 50 to C. Ifhydrochloric acid is employed in the extraction step, no water is addedin the hydrolysis step. If anhydrous acid is used, the acid is dilutedto an approximately 50% solution in water prior to addition to thediesel cut. Hydrolysis results in the formation of a furtheracidinsoluble organic phase and aqueous fraction. The latter fraction isneutralized with a base, illustratively, ammonia or sodium hydroxide, toyield an organic fraction and a water-containing phase. This organicfraction is a concentrated mixture of weak nitrogenous organic baseshaving a molecular weight of to 200. This organic phase is substantiallywater-soluble and reactive with sulfuric acid, and is referred tohereinafter as the broad unrefined fraction.

Particularly useful in that they assure uniform properties within evennarrower and more preferred parameters than the initial broad unrefinedfraction are those fractions of the foregoing product which whendesalted, dried and distilled by conventional techniques are recoveredabove and below 580F. The desalting step is accomplished using an inertorganic solvent, desirably dioxane, ether or benzene followed byfiltration; water is then azeotroped out or, alternatively, aconventional drying agent added, and the solvent sequentially flashedoff.

The exact composition of the broad unrefined fraction, the narrowerfraction recovered below 5 80F referred to hereinafter as thedistillate", and that fraction recovered above 580F., referred tohereinafter as the high temperature residue, is not fully known.Generally, they are represented, although it is not intended thatcharacterization be relied upon, as containing heterocyclic nitrogenouscompounds, the heterocyclic ring structures of which are selected fromfive and six member rings and mixtures thereof containing one nitrogenatom and four and five carbon atoms respectively; the foregoing eitherunsubstituted; or substituted with an unsubstituted fused benzene ring,one or more alkyl moieties, a fused alkyl-substituted benzene ring, orone or more alkyl moieties and said substituted or unsubstituted fusedbenzene ring. The fusion, where it occurs, is normally in the2,3-position of the heterocyclic ring. The foregoing heterocycliccompounds are thus predominantly quinolines, pyrroles, indoles,pyridines, and possibly acridines and condensation products orheterocyclic polymers thereof in which the foregoing compounds areunsubstituted and substituted; predominantly alkyl-substituted, it isbelieved. Presumably, the broad unrefined fraction, distillate and hightemperature residue contain many of the nitrogenous compounds which arebelieved to occur in unitaite such as the 3-ethylpyridine,2,3,5-trimethylpyridine, pyridine, condensation products formed in thecoking step to form the broad unrefined fraction, pyrrole, 2-methylpyrrole, possibly l-methylpyrrole, and other loweralkyl-substituted pyrroles and condensation products thereof, describedby J. M. Sugihora and D. P. Sorensen, Journal of the American Society,vol. 77, pages 963 to 966 (Feb. 20, 1965).

3 The organic phase designated as the broad unrefined fraction used inthe practice of this invention and recovered as described above, priorto desalting, drying or distillation, has, typically, physicalproperties recited in Table I:

Pour Point, F. Viscosity. centipoises at 77F. 32 Average molecularweight 185 Total nitrogen, by weight 7.8 Basic nitrogen. by weightTertiary amine nitrogen, by weight Carbon, by weight Hydrogen, by weightSulfur, by weight Oxygen, by weight This fraction, constituting one ofthe desired additive products of the invention, will normally retain aresidue of mineral acid salts remaining from the fractionation stepsdiscussed hereinabove and used in securing the product, for example,sodium sulfate.

The desalted, dried distillate of the foregoing initial fraction boilingbelow 580F. [304 C.] is a deep red oil with a characteristic odor,eighty volume percent of which forms water-soluble salts with 50%sulfuric acid.

This distillate is characterized by the physical properties recited inthe following Table II:

The residue of heterocyclic compounds boiling above 580F. (304C.) andremaining after removal of the distillate characterized in Table I1 iscomposed predominantly, it is believed, of highly alkylated quinolinesand indoles in addition to heterocyclic polymers formed from reactivepyridines, quinolines, indoles and pyrroles, as noted above; that is,those of the foregoing compounds having a reactive hydrogen in the alphaposition. This residue is characterized by the following physicalproperties:

TABLE [I1 Specific gravity at 77F. 1.059 at 60F. 1.064 APl gravity 1.4

Distillation Vol. 7: F. at 760 mm (ASTM D-1S8) Start 598 10 626 30 64350 659 692 888 End point Cracked Pensky-Manens flash point, F. 360 Pourpoint, F. +80 Viscosity, centistokes at F. 492 Average molecular weight280 Water, by weight 0.34 Total nitrogen, by weight 6.94 Basic nitrogen,by weight 3.32 Tertiary amine nitrogen, by weight 3.31 Sulfur, by weight0.68

Uintaite, or gilsonite or uintahite as it is also designated, itsorigin, properties, types and methods of recovery and composition arefurther described by H. Abraham in Asphalts and Allied Substances, 5thEdition, vol. I, D. von Nostrand Co., Inc., New York, N. Y., pages 250et seg. (1945); and Encyclopedia of Chemial Technology, 2d Edition,Kirk-Othmer, pages 527 to 533 (1966) and the references recited therein.

The foregoing fractions have been produced sporadically by the AmericanGilsonite Company, Salt Lake City, Utah; the broad unrefined fractionbearing the trade designation GN-l03; the distillate being referred toas GN-200; and the high temperature residue being termed GN-20l.

These products, which have been found frequently heretofore to possessproperties lacking in uniformity in many of their areas of application,indicate satisfactorily uniform results when employed as antioxidants asprovided herein.

The uintaite derivative antioxidants prepared according to the practiceof the invention while particularly useful in crankcase motor oilformulations wherein they permit operation of equipment over widertemperature ranges than would otherwise be feasible have utility as wellin lubricant formulations for gas turbine and hydraulic systems.

Concentrations in hydrocarbon lubricating oil of from about 0.01 toabout 50% by weight of one of the foregoing uintaite derived mixtures,that is, the broad unrefined fraction, the distillate or the hightemperature residue are contemplated. In the lubricating oilconcentrates which are formulated for storage and/or transport and aresubsequently blended into additional base oil to form finished motor oilformulations suitable for crankcase use, the content of the uintaiteantioxidant normally ranges from about 10 to about 50 weightConcentrations of these antioxidants in the finished motor oilcomposition are advantageously within the range of about 0.1 to about 10weight The nitrogenous antioxidant mixtures of the invention replace thesignificantly more expensive conventional amine antioxidants exemplifiedby the phenylnaphthyl amines, phenothiazine and diphenylamine.Advantageous proportions of the heterocyclic nitrogenous compositions ofthe invention are within the range 0.1 to 5 by weight and most desirablyabout 0.5 to 1.5 by weight. The lubricant compositions of the inventionare also fortified normally with conventional additives such asanti-wear agents, dispersants corrosion inhibitors antifoamants andother standard additives.

The hydrocarbon mineral oils employed in this invention can be paraffinbase, naphthene base, or mixed paraffin-naphthene base distillate orresidual oils. The lubricating oil base generally has been subjected tosolvent refining to improve its lubricity and viscosity temperaturerelationship as well as solvent dewaxing to remove waxy components andto improve the pour of the oil. Generally, mineral lubricating oils havean SUS viscosity at 100F. between 50 and 1000 may be used in theformulation of the improved lubricants of this invention although theviscosity range wil usually fall between 70 and 300 SUS at 100F. A blendof base oils can be employed to provide a suitable base oil for either asingle or multigrade motor oil.

An antiwear agent desirably incorporated in the lubricating oilcompositions of the invention is zinc dithiophosphate characterized bythe formula:

RD S

P-S Zn R0 in which R is a hydrocarbyl radical or a hydroxy-substitutedhydrocarbyl radical having from 4 to 12 carbon atoms. The preferred zincdithiophosphates are those in which R represents an alkyl radical havingfrom 4 to 8 carbon atoms. Examples of suitable compounds include zincisobutyl 2-ethylhexyl dithiophosphate, zinc di(Z-ethylhexyl)dithiophosphate, zinc isoamyl 2-ethylhexyl dithiophosphate, zincdi(phenoxyethyl) dithiophosphate, zinc di(2,4 diethylphenoxyethyl)dithiophosphate and most desirably zinc isopropylmethyl isobutylcarbinyl dithiophosphate. In general, these compounds are employed inthe oil composition in a concentration ranging from about 0.1 to 5.0%with the preferred concentration ranging from about 0.5 to 1.5%.

These compounds can be prepared from the reaction of a suitable alcoholor mixture of alcohols with phosphorus pentasulfide. They areillustrated in U.S. Pat. Nos. 2,344,395 and 3,293,181.

Most desirable of the foregoing is zinc isopropyl methyl isobutylcarbinol dithiophosphate prepared by reaction of amethylisobutyl-carbinol and isopropanol with phosphorus pentoxide in amole ratio respectively lof about 2.7:2.3:1.0.

Dispersants which may be included in the compositions of the inventionare the monohydrocarbyl thiophosphonates characterized by the formula:

in which R is a hydrocarbyl radical having at least 12 carbon atoms andR and R are selected from the group consisting of hydrogen andmonovalent aliphatic hydrocarbyl radicals containing 1 to 6 caron atoms,and X is predominantly, or normally, sulfur.

Mono-hydroxyalkyl hydrocarbyl thiophosphates can be prepared by reactingan alkylene oxide, such as ethylene oxide, alkylene carbonates, such asethylene carbonate or propylene carbonate, with a hydrocarbylthiophosphonic acid. The reaction of alkylene carbonate with hydrocarbylthiophosphonic acid is usually effected in the presence of an alkalinecatalyst, such as potassium carbonate.

The hydrocarbyl thiophosphonic acid employed in preparing themono-hydroxyalkyl thiophosphate may be represented by the generalformula:

wherein R is a hydrocarbyl radical which may be aromatic aliphatic orcycloaliphatic in nature and which usually contains 12 or more carbonatoms and X is sulfur or a mixture comprising a major proportion ofsulfur and a minor proportion of oxygen. The R radical in this formulais advantageously a polyolefin radical such as polyisobutylene orpolypropylene having an average molecular weight between about 250 and50,000 since such materials are the preferred materials for reactionwith P S The preferred hydrocarbyl radical is a polybutene radicalhaving a molecular weight between 500 and 5,000.

The hydrocarbyl thiophosphonic acids of the above formula areconventionally prepared by the reaction of P S with a hydrocarbon, thereaction mixture consisting of between about 5 and 40 weight P S at an'elevated temperature of between about and 320C. in a non-oxidizingatmosphere, for example, under a blanket of nitrogen followed byhydrolysis of the resulting product by contact with steam at atemperature between about 100 and 260C. Steam treatment of the P 5hydrocarbon reaction product results in its hydrolysis to form inorganicphosphorus acids and a hydrocarbyl thiophosphonic acid of the structureshown above.

The inorganic phosphorus acids are removed from the hydrolyzed reactionproduct prior to reaction with alkylene oxide or alkylene carbonate toform the mono-hydroxyalkyl hydrocarbyl thiophosphates. Removal of theinorganic phosphorus acids from the hydrolyzed product can be effectedby the procedures disclosed in U.S. Pat. Nos. 2,951,835 and 2,897,512wherein removal is effected by contact with synthetic hydrous alkalineearth metal silicates and synthetic hydrous alkali metal silicatesrespectively. Inorganic phosphorus acid can also be removed byextraction with anhydrous methanol as disclosed in U.S. Pat No. 3 ,1 35,7 19.

An alkylene oxide is reacted with the hydrocarbyl thiophosphonic acid inabout an equimolar basis in the absence of catalyst to form themone-hydroxyalkyl thiophosphonate additives of this invention. Thepreparation of this component is fully described in U.S. Pat. No.3,272,744 and this disclosure is incorporated in the presentapplication.

The preferred thiophosphonates for use herein are mono(B-hydroxyethyl)alkene thiphosphonates, and most desirably mono(B-hydroxyethyl)polybutene thiophosphonate having an average molecular weight of about1100. A phosphonate such as the foregoing is normally present in thelubricating oil in an amount of about 0.5 to 5.0 weight Another suitableadditive for lubricant composition of the invention is a calciumcarbonate overbased calcium sulfonate component containing from aboutmoles to 30 moles of dispersed calcium carbonate per mole of calciumsulfonate and having a Total Base Number from about 100 to 500. Thepreferred overbased calcium sulfonate will have from about 10 to molesof dispersed calcium carbonate per mole of calcium sulfonate. Theseoverbased substances provide a high level of alkalinity in thelubricating oil composition useful in combating deleterious action ofcorrosive substances as well as providing dispersancy. They areadvantageously present in amounts of between about 0.25 and 5 wt.

In general, an overbased calcium sulfonate is prepared by reacting acalcium sulfonate (derived from the reaction of a natural or syntheticsulfonic acid having a molecular weight ranging from about 350 to 600with hydrated lime) with carbon dioxide at an elevated temperature,135-l60F., for an extended time period of several hours and under totalreflux conditions. Thereafter the reaction mixture is filtered torecover an approximately 45 percent oil solution of calcium carbonateoverbased calcium sulfonate prescribed above. The preparation of thiscomponent is fully described in U.S. Pat. No. 3,537,996 and thedisclosure of this reference is incorporated herein.

An effective dispersant and viscosity index improving component alsocontemplated for use in the lubricant oils provided herein is a basicamine-containing addition-type copolymer formed of a plurality ofpolymerizable ehtylenically unsaturated compounds, at least one of whichis amino-free and contains from 8 to about 18 carbon atoms in analiphatic hydrocarbon chain, preferably predominantly straight chain innature, and one of which as it exists in the polymer contains a basicamino nitrogen in the side chain, in an amount by weight of said polymerof 0.05 to 3.5

It is essential that at least one of the monomeric components employedin making the polymer should introduce an oil-solubilizing or oleophilicstructure to insure that the polymer is soluble to the extent of atleast 0.1% by weight in naphthenic or paraffinic lubricating oils. Inaddition, the presence of basic amino groups, either primary, secondaryor tertiary is necessary to impart the unique sludge dispersingproperties which characterize these polymers. The proportion of basicamino nitrogen is best expressed in weight percent based on the totalcopolymer and should be within the range of 0.05 to 3.5 weight asdescribed above. Elaborating on the description provided hereinabove,introduction of the basic amino nitrogen structure can be accomplishedby the use of at least one monomeric component containing the aminogroup or by use of a monomer containing a group which is reactive, whenpresent in the polymer, toward ammonia, or primary or secondarynon-aromatic amines. These monomers can also contain oleophilicstructures that will assist in contributing to the requisite oilsolubility. In addition, some the polymers coming within the scope ofthis invention can, without sacrificing either oil solubility ordispersing properties, include certain proportions of monomers that donot themselves yield oil soluble polymers.

Most preferred of these methacrylate-containing polymers is thecopolymer of butyl, lauryl, stearyl and dimethylaminoethyl methacrylatewherein the butyl, lau ryl, stearyl and dimethylamino monomers areincorporated in a weight ratio respectively of 21532214. It

should be understood, additionally, that lauryl methacrylate monomercharged to the polymerization reaction frequently contains about 25 to28% by weight of myristyl methacrylate and the stearyl methacrylatemonomer includes, by weight, about 32 to 44% of cetyl methacrylate andpossibly up to 16% by weight of lower hydrocarbyl-containingmethacrylates.

Copolymers useful in the practice of the invention can be prepared byconventional bulk, solution, or dispersion polymerization methodsinvolving known initiators, including oxygen-yielding compounds, such asbenzoyl peroxide, and azo compounds, such asalpha,alpha'-azo-diisobutyronitrile. The polymerization processesusually are carried out in an inert atmosphere, e.g. nitrogen or carbondioxide, at temperatures ranging from 30 to 150C., depending on thecatalyst used and generally at temperatures between 50C. and C. whenalpha, alpha-azodiisobutronitrile is used as catalyst. It is importantto carry the copolymerization substantially to completeness so that nounpothose of the original monomer mixture. The method of preparing thesepolymers is described in detail in U.S. Pat. No. 2,737,496 and thisdisclosure is incorporated herein.

The above described methacrylate copolymer is employed in thelubricating oil in a concentration ranging from about 0.5 to 5% with thepreferred concentration ranging from about 1 to 4%.

A suitable anti-foaming agent is a dimethyl silicone polymer having akinematic viscosity at 25C. of about centistokes and above. A verysatisfactory antifoaming agent for this purpose is prepared by diluting10 grams of a dimethyl silicone polymer (1000 centistokes at 25C.) withkerosene to provide a solution of 100 cubic centimeters. From 0.005 to0.025% by weight of this concentration is generally employed to providefrom 50 to 200 parts per million of the silicone polymer based on thelubricating oil composition.

An example of a crankcase lubricant composition for use herein willcomprise a base oil blend such as the foregoing in an amount of at least77 to about 99 weight (e.g. 99.05 weight and preferably about 89 (e.g.89.46 weight and will contain from about 0.5 to 8 weight (e.g. 5 weightof an oil concentrate containing about 35% by weight of a basic aminonitrogen-containing addition type of alkyl esters of methacrylic acid,that is, butyl, lauryl, stearyl and dimethyl amino-ethyl methacrylatesin approximately 21:53:22z4 weight ratios (as described in U.S. Pat. No.2,737,496); about 0.25 to 5.0 weight for example, 2 weight of an oilconcentrate containing 50 weight of a calcium carbonate overbasedcalcium sulfonate of a 300 TBN; about 0.1 to 5, and for example, about2.5 weight of an oil concentrate containing about 44% by weight of anaphthenic lubricating oil of an SUS viscosity of about 100 at 100F.mono(B-hydroxyethyl) alkene thiophosphonate and from about 0.50 to 5weight illustratively 0.54 weight as indicated above, of a heterocyclicnitrogenous-containing mixture of the invention.

The formulations so described are supplied by standard procedures to thecrankcase of the engine. When the engine is in operation the oil willattain elevated temperatures and, in accordance with the invention, theviscosity increases in the oil, which would occur in the absence of theuintaite derivatives of the invention,

will be found to be significantly alleviated by their presence. Thus, ithas been found that at 100F. from approximately 700% to 100% reductionin viscosity increase is realized by use of the compositions of theinvention at a concentration of one weight percent in the lubricantblend. The present invention is further illustrated by the followingexample:

EXAMPLE This example illustrates, in comparative test procedure, theoxidative-thickening resistant properties imparted to typical crankcaseengine lubricating oils under high temperature operating conditions bythe practice of this invention.

The mixture of the invention, the high temperature residue, distillateand broad unrefined fraction derived from uintaite were incorporatedindividually in lubricant oil compositions incorporating, as well, thefull complement of additives shown in Table IV, and tested, as alsoshown in Table IV, in a sequence of Runs for terminal viscosity,percentage increases in viscosity and the period required before break,if any. The additives of the invention were incorporated in like amountsin each of Runs 1, 2 and 3 in a test oil formulation designatedComposition A and the test results secured using identical testprocedures. A control Run 4, made for purposes of comparison and theresults of which thick Fiberglas insulation about the outside. The teststand included an intake air temperature control to maintain aprescribed carburetor inlet air temperature. The automotive radiator wassubmerged in a water 5 tank with means to control the engine jackettemperature.

After a 3% hour break-in, the engine was operated at the following testconditions:

Approximately 5 gallons of test oil are required for each run. About 600gallons of gasoline is used in each run as fuel.

In this test the oils were runs, as indicated, for 40 hours of total andcontinuous testing time with samples being removed every four hours, andboth viscosity and infrared nitro-oxidation patterns monitored.

The test lubricant oil, Composition A, incorporated a blend of mineraloils of lubricating viscosity having the also appear in Table IV, wasundertaken under identifollowing inspection tests:

cal conditions, excluding the additives of the invention.

The test procedure employed in all four runs was one ggg g l :8 whichcorrelates the results of field trials with the thickviscosity, eningproperties of motor oils and is designed to simu- (emawlated) %28 lateextreme service conditions in a road test. In this 210?: 44

test procedure, a 1969 Ford 289-CID V-8 engine was installed on adynamometer test stand instrumented to control engine operatingconditions. The engine was modified by replacing the filter housing witha blank plate and by enclosing the engine oil pan with l-inch Thelubricant oil included the components and weight percentages thereofrecited in Table IV, as follows:

TABLE IV Run No. l 2 3 4 percentages of components by weight 91.56 91.56

ppm

100 ppm 100 ppm 100 ppm None None None None 37 hrs. 29 hrs.

Copolymer of butyl. lauryl, stearyl and dimcthylaminoethyl methacrylatesin 21:53:22z4 weight ratio. Percentages of myristyl. cetyl and otherlower methacrylate monomers are incorporated with the lauryl and stcarylmonomers charged.

Approximately moles of dispersed calcium carbonate per mole of calciumsulfonate. 300 TBN.

No break observed. DIR: infra-red nitro oxidation pattern.

It will be evident from the foregoing Table IV that the composition ofRun 4, from which the additives of the invention were excluded,manifested oxidative breaks as measured by viscosity and infra-rednitro-oxidation patterns at about 27 hours and 22 hours respectively.These breaks are significant in that thickening of the lubricant oiloccurs characteristically very rapidly after these breaks are found andoften lead in commercial practice with many typical lubricantcompositions to engine failure. It will be equally evident that thesebreaks did not occur under the rigorous test conditions employed wherehigh temperature residue or broad unrefined fraction is incorporated inthe lubricant composition; and occurs where distillate is incorporated(Run 2) only after the passage of a significantly greater period oftime, i.e. 37 hours and 29 hours respectively, than is seen in thecontrol of Run 4.

Thus, when additives of the type described are used, the timestranspiring until an oxidation break occurs (as measured by eitherviscosity increase or infra-red nitro-oxidation patterns) aresignificantly increased, indicating clearly the superior performance ofcrankcase engine oils incorporating the nitrogenous compositions of theinvention. This conclusion is reinforced by the comparison of terminalviscosities secured in each of the foregoing runs as recited in Table IVabove.

The method of the invention involves operating an internal combustionreciprocating engine employing the lubricant oil compositions of theinvention.

It will be evident that the terms and expressions which have beenemployed are used as terms of description and not of limitation. Thereis no intention in the use of such terms and expressions of excludingequivalents of the features shown and described or portions thereof andit is recognized that various modifications are possible within thescope of the invention claimed.

We claim:

1. A lubricant oil composition resistant to oxidative thickening atelevated temperatures comprising a mineral lubricating oil containingfrom 0.01 to 50% by weight of a heterocyclic nitrogenous-containingmixture derived from uintaite and distilled therefrom by a procedurethat comprises subjecting uintaite to a cracking temperature within therange of about 885 to about 910F. to yield a fraction boiling in therange of about 400 to 650F. which is sequentially treated with a strongmineral acid to form an acid phase and an acid insoluble organic phase;hydrolyzing said acid phase to provide an acid insoluble organicfraction and an aqueous fraction; neutralizing the latter aqueousfraction with a base to yield further organicand water-containingphases; and recovering said organic phase comprising said heterocyclicnitrogenous-containing mixture therefrom.

2. The lubricant oil composition claimed in claim 1 wherein said organicphase occurring after acid-treatment, hydrolysis, neutralization andfinal removal of said water-containing phase therefrom, is desalted,dried and recovered upon ditillation thereof up to a temperature of580F.

3. The lubricant oil composition as claimed in claim 1 wherein saidorganic phase occurring after acid-treatment, hydrolysis, neutralizationand final removal of said water-containing phase therefrom, is desalted,dried and the fraction boiling at and below 580F. removed upondistillation; and the residue remaining recovered upon distillationabove 580F.

4. A lubricant oil composition as claimed in claim 1 wherein saidcomposition comprises a mineral lubricating oil and from 0.10 to 10% byweight of the said heterocyclic nitrogenous-containing mixture.

5. A lubricant oil composition as claimed in claim 2 wherein saidcomposition comprises a mineral lubricating oil and from 0.10 to 10% byweight of the said heterocyclic nitrogenous-containing mixture.

6. A lubricant oil composition as claimed in claim 3 wherein saidcomposition comprises a mineral lubricating oil and from 0.10 to 10% byweight of the said heterocyclic nitrogenous-containing mixture.

7. A lubricating oil as claimed in claim 1 wherein said oil includes 0.1to 5.0% of a zinc dithiophosphate characterized by the formula:

in which R is a hydrocarbyl radical or a hydroxy substituted hydrocarbylradical having from 4 to 12 carbon atoms, 0.5 to 5.0 percent ofmonohydroxyalkyl hydrocarbyl thiophosphonate characterized by thegeneral formula:

in which R is a hydrocarbyl radical having at least 12 carbon atoms, Rand R are selected from the group consisting of hydrogen and monovalentaliphatic hydrocarbyl radicals containing 1 to 6 carbon atoms and X issulfur, from 0.5 to 5.0% of an oil-soluble, basic aminonitrogen-containing addition type methyacrylate copolymer derived froman alkyl methacrylate in which the alkyl radical has from 4 to 20 carbonatoms and dialkylaminoalkyl methacrylate in which the alkyl radicalshave a total of 4 to 8 carbon atoms, said copolymer containing 0.05 to3.5% by weight of basic amino nitrogen and having an inherent viscosityof 0.1 to 3.0 and from 0.25 to 5% of calcium carbonate overbased calciumsulfonate having from about 5 to 30 moles dis- 13 persed calciumcarbonate per mole of calcium sulfonate and having a Total Base Numberranging from l to 500.

8. A crankcase engine oil as claimed in claim 2 wherein said oilincludes 0.] to 5.0% of a zinc dithiophosphate characterized by theformula:

in which R is a hydrocarbyl radical or a hydroxy substituted hydrocarbylradical having from 4 to 12 carbon atoms, 0.5 to 5.0% ofmonohydroxyalkyl hydrocarbyl thiophosphonate characterized by thegeneral formula:

in which R is a hydrocarbyl radical having at least 12 carbon atoms, Rand R are selected from the gourp consisting of hydrogen and monovalentaliphatic hydrocarbyl radicals containing 1 to 6 carbon atoms and X issulfur, from 0.5 to 5.0% of an oil-soluble, basic aminonitrogen-containing addition type methacrylate copolymer derived from analkyl methacrylate in which the alkyl radical has from 4 to 20 carbonatoms and dialkylaminoalkyl methacrylate in which the alkyl radicalshave a total of 4 to 8 carbon atoms, said copolymer containing 0.05 to3.5% by weight of basic amino nitrogen and having an inherent viscosityof 0.1 to 3.0 and from 0.25 to of calcium carbonate overbased calciumsulfonate having from about 5 to 30 moles dispersed calcium carbonateper mole of calcium sulfonate and having a Total Base Number rangingfrom 100 to 500.

i 9. A crankcase engine oil as claimed in claim 3 wherein said oilincludes 0.1 to 5.0% of a zinc dithiophosphate characterized by theformula:

1 l in which R is a hydrocarbyl radical or a hydroxy substi- ,tutedhydrocarbyl radical having from 4 to 12 carbon :atoms, 0.5 to 5.0% ofmonohydroxyalkyl hydrocarbyl thiophosphonate characterized by thegeneral formula:

14 copolymer derived from an alkyl methacrylate in which the alkylradical has from 4 to 20 carbon atoms and dialkylaminoalkyl methacrylatein which the alkyl radicals have a total of 4 to 8 carbon atoms, saidcopolymer containing 0.05 to 3.5% by weight of basic amino nitrogen andhaving an inherent viscosity of 0.1 to 3.0 and from 0.25 to 5% ofcalcium carbonate overbased calcium sulfonate having from about 5 tomoles dispersed calcium carbonate per mole of calcium sulfonate andhaving a Total Base Number ranging from 100 to 500.

10. A lubricating oil as claimed in claim 4 wherein the oil includes 0.1to 5.0% of a zinc dithiophosphate characterized by the formula:

in which R is a hydrocarbyl radical or a hydroxy substituted hydrocarbylradical having from 4 to 12 carbon atoms, 0.5 to 5.0% ofmonohydroxyalkyl hydrocarbyl thiophosphonate characterized by thegeneral formula:

in which R is a hydrocarbyl radical having at least 12 carbon atoms, Rand R are selected from the group consisting of hydrogen and monovalentaliphatic hydrocarbyl radicals containing 1 to 6 carbon atoms and X issulfur, from 0.5 to 5.0% of an oil-soluble, basic aminonitrogen-containing addition type methacrylate copolymer derived from analkyl methacrylate in which the alkyl radical has from 4 to 20 carbonatoms and dialkylaminoalkyl methacrylate in which the alkyl radicalshave a total of 4 to 8 carbon atoms, said copolymer containing 0.05 to3.5% by weight of basic amino nitrogen and having an inherent viscosityof 0.1 to 3.0 and from 0.25 to 5% of calcium carbonate overbased calciumsulfonate having from about 5 to 30 moles dispersed calcium carbonateper mole of calcium sulfonate and having a Total Base Number rangingfrom to 500.

11. A lubricating oil as claimed in claim 5 wherein said oil includes0.1 to 5.0% of a zinc dithiophosphate characterized by the formula:

in which R is a hydrocarbyl radical or a hydroxy substituted hydrocarbonradical having from 4 to 12 carbon atoms, 0.5 to 5.0% ofmonohydroxyalkyl hydrocarbyl thiophosphonate characterized by thegeneral formula:

in which R is hydrocarbyl radical having at least 12 carbon atoms, R andR are selected from the group consisting of hydrogen and monovalentaliphatic hydrocarbyl radicals containing 1 to 6 carbon atoms and X issulfur, from 0.5 to 5.0% of an oil-soluble, basic aminonitrogen-containing addition type methacrylate copolymer derived from analkyl methacrylate in which the alkyl radical has from 4 to carbon atomsand dialkylaminoalkyl methacrylate in which the alkyl radicals have atotal of 4 to 8 carbon atoms, said copolymer containing 0.05 to 3.5% byweight of basic amino nitrogen and having an inherent viscosity of 0.1to 3.0 and from 0.25 to 5% of calcium carbonate overbased calciumsulonate having from about 5 to 30 moles dispersed calcium carbonate permole of calcium sulfonate and having a Total Base Number ranging from100 to 500.

12. A crankcase engine oil as claimed in claim 6 wherein said oilincludes 0.1 to 5.0% of a zinc dithiophosphate characterized by theformula:

in which R is a hydrocarbyl radical or a hydroxy substituted hydrocarbonradical having from 4 to 12 carbon atoms, 0.5 to 5.0% ofmonohydroxyalkyl hydrocarbyl thiophosphonate characterized by thegeneral formula:

in which R is hydrocarbyl radical having at least 12 carbon atoms, R andR are selected from the group consisting of hydrogen and monovalentaliphatic hydrocarbyl radicals containing 1 to 6 carbon atoms and X issulfur, from 0.5 to 5.0% of an oil-soluble, basic aminonitrogen-containing addition type methacrylate copolymer derived from analkyl methacrylate in which the alkyl radical has from 4 to 20 carbonatoms and dialkylaminoalkyl methacrylate in which the alkyl radicalshave a total 0f4 to 8 carbon atoms, said copolymer containing 0.05 to3.5% by weight of basic amino nitrogen and having an inherent viscosityof 0.1 to 3.0 and from 0.25 to 5% of calcium carbonate overbased calciumsulfonate having from about 5 to 30 moles dispersed calcium carbonateper mole of calcium sulfonate and having a Total Base Number rangingfrom to 500.

13. A composition according to claim 7 wherein said oil includes amineral lubricating oil having an SUS viscosity at 100F. of between 50and 1000.

14. A composition according to claim 8 wherein said oil includes amineral lubricating oil having an SUS viscosity at 100F. of between 50to I000.

15. A composition according to claim 9 wherein said oil includes amineral lubricating oil having an SUS viscosity at l00F. of between 50and i000.

1. A LUBRICANT OIL COMPOSITION RESISTANT TO OXIDATIVE THICKENING ATELEVATED TEMPERATURE COMPRISING A MINERAL LUBRICATING OIL CONTAININGFROM 0.01 TO 50% BY WEIGHT OF A HETEROCYCLIC NITROGENOUS-CONTAININGMIXTURE DERIVED FROM UINTAITE AND DISTILLED THEREOF BY A PROCEDURE THATCOMPRISES SUBJECTING UINTATIE TO A CRACKING TEMPERATURE WITHIN THE RANGEOF ABOUT 885* TO ABOUT 910*F. TO YIELD A FRACTION BOILING IN THE RANGEOF ABOUT 400* TO 650*F. WHICH IS SEQUENTIALLY TREATED WITH A STRONGMINERAL ACID TO FORM AN ACID PHASE AND AN ACID INSULUBLE ORGANIC PHASE,HYDROLYZING SAID ACID PHASE TO PROVIDE AN ACID INSOLUBLE ORGANICFRACTION AND AN AQUEOUS FRACTION, NEUTRALIZING THE LATTER AQUEOUSFRACTION WITH A BASE TO YIELD FURTHER ORGANIC- AND WATER-CONTAININGPHASE, AND RECOVERING SAID ORGANIC PHASE COMPRISING SAID HETEROCYCLICNITROGEOUS-CONTAINING MIXTURE THEREFROM.
 2. The lubricant oilcomposition claimed in claim 1 wherein said organic phase occurringafter acid-treatment, hydrolysis, neutralization and final removal ofsaid water-containing phase therefrom, is desalted, dried and recoveredupon ditillation thereof up to a temperature of 580*F.
 3. The lubricantoil composition as claimed in claim 1 wherein said organic phaseoccurring after acid-treatment, hydrolysis, neutralization and finalremoval of said water-containing phase therefrom, is desalted, dried andthe fraction boiling at and below 580*F. removed upon distillation; andthe residue remaining recovered upon distillation above 580*F.
 4. Alubricant oil composition as claimed in claim 1 wherein said compositioncomprises a mineral lubricating oil and from 0.10 to 10% by weight ofthe said heterocyclic nitrogenous-containing mixture.
 5. A lubricant oilcomposition as claimed in claim 2 wherein said composition comprises amineral lubricating oil and from 0.10 to 10% by weight of the saidheterocyclic nitrogenous-containing mixture.
 6. A lubricant oilcomposition as claimed in claim 3 wherein said composition comprises amineral lubricating oil and from 0.10 to 10% by weight of the saidheterocyclic nitrogenous-containing mixture.
 7. A lubricating oil asclaimed in claim 1 wherein said oil includes 0.1 to 5.0% of a zincdithiophosphate characterized by the formula:
 8. A crankcase engine oilas claimed in claim 2 wherein said oil includes 0.1 to 5.0% of a zincdithiophosphate characterized by the formula:
 9. A crankcase engine oilas claimed in claim 3 wherein said oil includes 0.1 to 5.0% of a zincdithiophosphate characterized by the formula:
 10. A lubricating oil asclaimed in claim 4 wherein the oil includes 0.1 to 5.0% of a zincdithiophosphate characterized by the formula:
 11. A lubricating oil asclaimed in claim 5 wherein said oil includes 0.1 to 5.0% of a zincdithiophosphate characterized by the formula:
 12. A crankcase engine oilas claimed in claim 6 wherein said oil includes 0.1 to 5.0% of a zincdithiophosphate characterized by the formula:
 13. A compositionaccording to claim 7 wherein said oil includes a mineral lubricating oilhaving an SUS viscosity at 100*F. of between 50 and
 1000. 14. Acomposition according to claim 8 wherein said oil includes a minerallubricating oil having an SUS viscosity at 100*F. of between 50 to 1000.15. A composition according to claim 9 wherein said oil includes amineral lubricating oil having an SUS viscosity at 100*F. of between 50and 1000.